Internal combustion engine

Abstract

An internal combustion engine having a plurality of banks; each having a cylinder provided to said banks comprising: an intake valve provided between said cylinder and an intake manifold a camshaft opening and closing said intake valve by means of mechanical power of said internal combustion engine; and a changing unit changing, according to an operating state of said internal combustion engine a phase angle of said camshaft said phase angle corresponding to a closing timing of said intake valve said banks differing from each other in most retarded phase angle changed by said changing unit.

Description

TECHNICAL FIELD[0001]The present invention relates to an internal combustion engine. In particular, the invention relates to an internal combustion engine having a plurality of banks that differ from each other in valve timing of a most retarded angle.BACKGROUND ART[0002]To an internal combustion engine mounted on a vehicle, a variable valve timing mechanism has conventionally been provided. The variable valve timing mechanism for example continuously and variably controls opening / closing timing of an intake valve by means of oil-hydraulic drive under electronic control so as to improve torque at low to medium speed, fuel economy and emission performance. The closing timing of the intake valve is set with higher priority given to startability when the internal combustion engine is started.[0003]For example, Japanese Patent Laying-Open No. 06-323168 discloses a control apparatus for an internal combustion engine promoting atomization of injected fuel at the start of the internal comb...

AI Technical Summary

Benefits of technology

[0008]An object of the present invention is to provide an internal combustion engine that achieves both of ensured startability and improved fuel economy.

Problems solved by technology

However, in the case where higher priority is given to fuel economy and the valve closing timing is further retarded, a resultant problem is that an in-cylinder pressure with which the internal combustion engine can be started cannot be obtained.

Thus, in the case where higher priority is given to the startability of the internal combustion engine to set the valve closing timing, it could occur that the valve closing timing cannot be set with higher priority given to fuel economy since the variable range of the intake-valve closing timing is limited.

In this case, the in-cylinder pressure with which the internal combustion engine can be started could not be obtained so that the startability is deteriorated.

A resultant problem is therefore that the ensured startability of the internal combustion engine and the improvement of fuel economy cannot be achieved simultaneously.

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